Metal-cutting shears



P 1951 w. M. SHOEFNEE 2,567,129

METAL CUTTING SHEARS Filed April 9, 1949 2 Sheets-Sheet 1 INVENTOR WILL IE M. Sl/OFFNER ATTORNEYS p 1951 w. M. SHOFFNER 7,

METAL CUTTING SHEAR-S Filed April 9, 1949 2 Sheets-Sheet 2 /N VE N TOR WILL/E M 8110mm ATTOPNiYS Patented Sept. 4, 1951 UNITED. STATES PATENT OFFICE METAL-CUTTING saunas Willie M. Shoflner, Dayton, Ohio Application April 9, 1949, Serial No. 89,133 s claims. (01.30-241) This invention relates to shears for cutting metal sheet and the like and particularly to shears especially adapted for taking relatively heavy cuts and for cuttingja round corners.

- Metal cutting shears according to the prior art generally consists of scissor-like arrangements in which the'two legs are cast or forged and are formed with hand l g'rips at one end and with cutting edges at the other end. The legs arevpivoted together by a central pin about which the legs rotate relatively in operation.

One serious drawback with a shears constructed in this manner is that only a relatively thin piece of metal can be out. If it is attempted to cut very heavy material? say greater than a sixteenth, then considerable difliculty is encountered not only in making the cut but in keeping the jaws from sliding over the metal instead of actually cutting through it.

Another drawback in connection with prior art shears which are constructed like scissors is that it is practically impossible to take two consecutive cuts at widely divergent angles unless at least one of the cutsextends considerably beyond the point of intersection of the cuts. It is even with some difliculty that curves are cut with the prior art type-shears.

It is evident that the utility of prior art metal cutting shears is definitely. limited, especially in connection with artisans installing heating systems and the like and who must be able to form many shapes from sheet metal.

The primary object of thepresent invention is to provide a metal cutting shears construction which overcomes the aforementioned disadvantages of prior art metal shears.

- Another object is to provide a metal cutting shears which can be constructed entirely of amped and formed parts rather than from castingand forgings if desired.

It is a particular object to provide a metal shears construction such that the. shears are capable of cutting metal much heavier than can be cut by shears constructed according to prior art practices.

Another particular object of this invention is to provide a metal cutting shears arrangement especially adapted for cutting around corners and sharp curves. 1

These and other objects and advantages will become-more apparent .upon reference to the following description taken in connection with the accompanying drawings in which:

Figure l is a side elevation of a shears constructed according to my. invention partly broken out in order to show the. construction and arrangement of the operative parts thereof;

Figure 2 is a view like.;Figure 1 but is taken from the other side thereof;

Figure 3 is an end view looking in from the left end of Figure 1;

- Figure 4 is a viewlooking as indicated by the arrow 4 in Figure 1; a

Figure 6 is a view like Figure 1 but showing 2 the shears blades moved together at the end of a cutting operation;

Figure 6 is a sectional view indicated by the 5 line 66 on Figure 2;

Figure '7 is a plan section indicated by line 1-1 on Figure 2;

Figures 8 and 9 are vertical sections indicated by lines 8-8 and 9-9 on Figure 2; 5

Figure 10 is a vertical sectional view indicated by line Ill-I 8 on Figure 3;

Figure 11 is a view looking up from beneath a' sheet of metal being cut by the shears with the shears turned ninety degrees to the direction of the previous cut for taking a new cut;

and

Figure 12 is a view like Figure 11 but looking fromthe top side of the sheet of metal.

Referringto the drawings somewhat more in detail the shears of this invention generally comprises a frame In havin a handle means l2 at one end thereof and comprising a pair of spaced side plates [4 rigidly interconnected as by rivet means l6 and having between their ends opposite the handle I2 a spacing member 3. At the handle end there may be the spacer 20 which maintain the side plates I 4 in sub.- stantial parallelism.

Spaced from the spacer I8 is a part 22 secured between the side plates l4 by rivets 24 and having a dependent portion 26. At the lower. end of the dependent portion 26 is a laterally offset foot part 28 extending toward the end of frame l0 opposite the handle l2 thereof.

As will be seen in Figures 2 and 3 the inner side of the foot part 28 is formed so as to .have a cuttingedge 30. This cutting edge 30 cooperates with a similar cutting edge 32 on the lower end of a bar 34 which is reciprocable in the rectangular passage formed in the frame Ill beabove frame l0 and receives a pivot pin 44 which mounts the left end of an upper handle or lever 46;"Lever" 46 carrie a roller 48 as by pin 50 and the said roller bears onthe upper endof bar, 34 as'indicated in Figures 1 and 5.

Bar 34' may have a cam shaped upper surface as at 52 if so desired. Roller 48 may have flats 54 on the side toward member l8 to provide clearance for movement of lever 45 and these flats may also act as stops to predetermine the limits of movement of lever 46;

Reference to Figures 2, 3, 6 and? will reveal that interposed between one side of bar 34 and one of the side plates l4 of the frame is a plate 56 split part way up as at 58 in alignment with one edgeof bar 34. A set screw 60 and clamping said bar in proper cutting alignment with cutting edge 30 on foot bar 28.

This provides a ready takeup for -relearances,

34 by manufacturing introduced around bar tolerances and by wear.

28 of the blade fixed in frame 10, it that the said part 26 is relieved as at 64- by an undercut extending axiaily along part 26 and in substantial alignment with .the cutting-v edges stil and 32. This relief permitsturning of the shears to,.some extent .in the material being cut-to. follow a's'traightline oracurve The foot part 28 .isrelieved bytransversely extending recess 66 which is substantially in alignment withv the .rear...edge of bar 34, {This recess is of advantage in permitting the shears to be turned sharply at the endof acut in. order to take a new cut in a difierent direction; This.is indicated in. Figures 11 and 12wherein 'the first cut taken by the shears is marked ligand the cutto be'taken marked 10. .It will beseen that the shear bladeshaye. been turned at substantially ninety degrees to their former It will beobservedthat cutting edges .30 and 32, are somewhat divergent. towardthe front of theshears as will bestbe seen in' Figures 1 and 2. and that the bar 34 is beveled o'if at its lowerend as atlz and that its point may be relieved as in-- dicatedat 14. A

Thelocation of pivot 44 forwardly of.. bar 34, and the locati'on of the bearing point of roller 48 on bar 34 forwardlyof its median line is of importance in keeping the shearing force at a minimum and in preventing the development of .high turning movements on the said bar. v It is also to be noted that when the in their open position: line connecting the central axesof pivots 44 and 50 issub'stantially parallelwith the. outtingedges of the blades. I'hus, when. the lever 46 ismoved down to its Figure 5 positionthe mechanical p.ur-.

shears are This is distinctly different f rom.the action of the usual type scissor-like shears where the force available for shearing the metal decreases as the cut proceeds. 7

It will also be noted that due .to the reciproca-i tory motion which blade 34 takes, the divergence between, the cutting edges. 3fl-and- .32- is consid-' erably less than that found in the=usual scissortype shears. This is. effective for. eliminatingto a great extent the tendency for the shears to slip on the metal when heavy cuts are being taken 7 Inoperation, assheet of metal-to be cut inserted between the. opened blades as indicated stationaryand acts as an anvil so thatlittle or nogdeformationof the' material being cut takes place. The reciprocatory nature of the blade 34 and the high mechanical advantage of lever 46 --permitheavy cuts to be taken. Also, as much or more thrust is available at the end of a cut as v -"-"is available at the beginning thereof due to the Regarding dependent part gs and foqt part will be noted lever, and-rolleryarrangement of this invention.

It will also benoted that all of the parts of thesh'e'ars of this invention can be made from stamped and press formed parts if desired and this offers '-a substantialsaving over castingor forging ofthe parts: It will be understood that this invention is susceptibleto modification-in order to adapt it to different usages and conditions and, according-ly, illlS desired'to comprehend such modifications within this invention as may fallwit'hin theseopeof'the appended claims.

I'cla'im: "1. In a shearshaving-a'frame'including a han-;

dle at one end; a first blade fixed in said frame adjacent" the other *end'and dependent therefrom," a second blade reciprocable in said frame i'rr-adirection generally perpendicular to the length ;of the frame, said 'blades'h'aving adjacent direction and that, the new cut .113 will register exactly with former cut 68.

. onsaid lever bearing on the end 'of'sa'id: "second blade opposite the cutting edge thereon,-andre-'- silient means acting on said second blade'for urging it-away from saidfirst blade to permit material'to' be-cut' to be inserted thereb'etween,

1; the said roller'b'ea'ring on said second blade between the median line thereof 'and'th'e side there" of toward the pivot for said lever. 2. In a han'd shears especially adapted forcutting meter first and second handle means pivoted together at one end; one of said handle as shown inFigure -l the means having a member dependent therefrom adjacent said one endand with a foot part ex tending toward the said one end having a cutting edge' along the side toward the said handle, said t I one handle means having a rectangular passage chase of the lever on blade 34 actually increases.

having a cutting edge'on its one end for coopera" tion with'the 'cuttingied'ge nn s'a'jid root part for shearing metal and the'like, and a roller on the by lthe .dotanddash outline vin Figure: 1. The;

or the. shears 'the metalnbeing cut ofiers no hindrance to the shears Operator as is customarily the case, with .the-usualtype shearsl nlsok the lower; shears blade is substantially other handlemeans positioned to engage the other end of said bar for actuating it in shear-' nag-movements, said member being relieved in a line 'withz'sai'dcutting edges, and said foot part being relieved by a transverse recess on its underneath side"immediately-opposite the rear edgecf said-barw '3. In a-shears: a frame comprising spaced plates having spacing means therebetw'een'and" meansrigidlyinterconnecting said plates and spacing means; a first bar rigid in said .frame spaced from one of said spacing means to define a rectangular passage in' the frame and having a laterally offset foot part extending lengthwise of--the framasaid foot parthaving'a cutting edge aligned-with one side wall of said passage, a sec'- ond bar slidable in'said passage and having abut ting-edge on the end'toward' said foot partfor cooperation with the 'edgethereon, a lever piv-' oted in said frame, "and a 'rolIer'on said lever overlyin the other end of said second-bar whereby substantially-all of the thrust on said second bar due to cutting loads is exerted axially thereof; a" notch in one edgexof'said second bar, a member havin one end in said swivell supported by said frame, and spring means acting on said bar to retract said second bar to se arate said edges. I

4. In a shearsi a frame comprising spaced plates having spacing means therebetween and means rigidly interconnecting said plates and spacing means, a first bar" rigid in said frame "spaced from one of said spacing means to define a rectangular passage in the frame and having a laterally offset foot part'extending lengthwise of the frame, said foot part having a cutting edge aligned with one side wall of said passage, a second bar slidable in said passage and having a cutting edge on the end toward said foot part for cooperation with the edge thereon, a lever pivoted in said frame, and a roller on said lever overlying the other end of said second bar whereby substantially all of the thrust on said second bar due to cutting loads is exerted axially thereof, and a plate member between said second bar and the other side wall of said passage adjustable for keeping said second car closely confined in said passage.

5. In a shears comprising a frame extending generally longitudinally and having handle means at one end, a barrigid with said frame between its ends and having an integral foot part offset laterally therefrom and extending toward the other end of the frame, the inner side of said foot part having a cutting edge on its upper side, another bar vertically reciprocable in said frame so as to pass closely by said inner side of said foot part and having a cutting edge on its lower end to cooperate with the cutting edge on said foot part, a lever overlying said handle means and pivoted to the other end of said frame beyond said other bar, and a roller on said lever engaging the upper end of said other bar so relative movement of the lever and frame will actuate said other bar in cutting movements, said roller having a flat thereon adapted to engage the frame and halt the lever in at least one of its extreme positions of movement.

6. In a shears comprising a frame extending generally longitudinally and having handle means at one end, a bar rigid with said frame between its ends and having an integral foot part offset laterally therefrom and extending toward the other end of the frame, the inner side of said foot part having a cutting edge on its upper side, another bar vertically reciprocable in said frame so as to pass closely by said inner side of said foot part and having a cutting edge on its lower end to cooperate with the cutting edge on said foot part, a lever overlying said handle means and pivoted to the other end of said frame beyond said other bar, and a roller on said lever engaging the upper end of said other bar so relative movement of the lever and frame will actuate said other bar in cutting movements, said roller having a fiat thereon adapted to engage the frame and halt the lever in at least one of its extreme positions of movement, said roller being arranged relative to the pivot axis of said lever so the mechanical advantage of said lever increases as it moves to actuate said other bar in cutting movements.

7. In a shears comprising a frame extending generally longitudinally and having handle means at one end, a bar rigid with said frame between its ends and having a dependent integral foot part ofifset laterally therefrom and extending toward the other end of the frame,

notch and its other end the inner side of said foot part having a cutting edge on its upper side, a second bar vertically reciprocable in said frame so as to pass closely by said inner side of said foot part and having a cutting edge on its lower end to cooperate with the cutting edge on said foot part, a third bar Y rigid with the frame and upstanding therefrom forming with said first bar a rectangular passage in which the second bar reciprocates, a lever overlying said handle means and pivoted to said third bar, and aroiler on said lever over said second bar, whereby movement of said lever about its pivot will actuate said other bar in cutting movements.

4 8. In a shears comprising a frame extending generally longitudinally and having handle means at one end, a bar rigid with said frame between its ends and having a dependent integral foot part offset laterally therefrom and extending toward the other end of the frame, the inner side of said foot part having a cutting edge on its upper side, a second car vertically reciproeable in said frame so as to pass closely by said inner side of said foot part and having a cutting edge on its lower end to cooperate with the cutting edge on said foot part, a third bar rigid with the frame and upstanding therefrom forming with said first bar a rectangular passage in which the second bar reciprocates, a lever overlying said handle means and pivoted to the said third bar, and a roller on said lever over said second bar, whereby movement of said lever about its pivot will actuate said other bar in cutting movements, said roller having a flat thereon that engages said third bar and stops said lever at the end of a working movement thereof.

9. In a shears having a frame including a handie at one end; a first blade fixed in said frame adjacent the other end and dependent therefrom, a second blade reciprocable in said frame in a direction generally perpendicular to the length of the frame, said blades having adjacent cutting edges generally perpendicular to the direction of reciprocation of said second blade, a lever pivoted on said frame between said second blade and the said other end of the frame, a roller on said lever bearing on the end of said second blade opposite the cutting edge thereon and forwardly of the center line thereof, and resilient means acting on said second blade for urging it away from said first blade to permit material to be cut to be inserted therebetween, said roller being so positioned that when said blades are open a line joining the pivot axes of the roller and lever is substantially parallel with said cutting edges whereby, as cutting of material by said blades proceeds, the mechanical purchase of said lever on said second blade increases.

WILLIE M. SHOFF'NER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 805,257 Brooks Nov. 21, 1905 879,900 Potstada Feb. 25, '1908 1,211,532 Blood Jan. 9, 1917 1,447,247 Hilsdorf Mar. 6, 1923 1,658,088 Kibler Feb. 7, 1928 2,058,719 Pigman Oct. 27, 1936 2,125,556 Gleich Aug. 2, 1938 2,329,387 Brenning Sept. 14, 1943 

